The Tor Browser: js/src/jit/StackSlotAllocator.h@6474c204b198

Cloned upstream origin tor-browser at tor-browser-31.3.0esr-4.5-1-build1
revision ID fc1c9ff7c1b2defdbc039f12214767608f46423f for hacking purpose.

     1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-

     2  * vim: set ts=8 sts=4 et sw=4 tw=99:

     3  * This Source Code Form is subject to the terms of the Mozilla Public

     4  * License, v. 2.0. If a copy of the MPL was not distributed with this

     5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

     7 #ifndef jit_StackSlotAllocator_h

     8 #define jit_StackSlotAllocator_h

    10 #include "jit/Registers.h"

    12 namespace js {

    13 namespace jit {

    15 class StackSlotAllocator

    16 {

    17     js::Vector<uint32_t, 4, SystemAllocPolicy> normalSlots;

    18     js::Vector<uint32_t, 4, SystemAllocPolicy> doubleSlots;

    19     uint32_t height_;

    21     void freeSlot(uint32_t index) {

    22         normalSlots.append(index);

    23     }

    24     void freeDoubleSlot(uint32_t index) {

    25         doubleSlots.append(index);

    26     }

    28     uint32_t allocateDoubleSlot() {

    29         if (!doubleSlots.empty())

    30             return doubleSlots.popCopy();

    31         if (height_ % 8 != 0)

    32             normalSlots.append(height_ += 4);

    33         return height_ += 8;

    34     }

    35     uint32_t allocateSlot() {

    36         if (!normalSlots.empty())

    37             return normalSlots.popCopy();

    38         if (!doubleSlots.empty()) {

    39             uint32_t index = doubleSlots.popCopy();

    40             normalSlots.append(index - 4);

    41             return index;

    42         }

    43         return height_ += 4;

    44     }

    46   public:

    47     StackSlotAllocator() : height_(0)

    48     { }

    50     void freeSlot(LDefinition::Type type, uint32_t index) {

    51         switch (type) {

    52 #if JS_BITS_PER_WORD == 32

    53           case LDefinition::GENERAL:

    54           case LDefinition::OBJECT:

    55           case LDefinition::SLOTS:

    56 #endif

    57           case LDefinition::INT32:

    58           case LDefinition::FLOAT32: return freeSlot(index);

    59 #if JS_BITS_PER_WORD == 64

    60           case LDefinition::GENERAL:

    61           case LDefinition::OBJECT:

    62           case LDefinition::SLOTS:

    63 #endif

    64 #ifdef JS_PUNBOX64

    65           case LDefinition::BOX:

    66 #endif

    67 #ifdef JS_NUNBOX32

    68           case LDefinition::TYPE:

    69           case LDefinition::PAYLOAD:

    70 #endif

    71           case LDefinition::DOUBLE:  return freeDoubleSlot(index);

    72           default: MOZ_ASSUME_UNREACHABLE("Unknown slot type");

    73         }

    74     }

    76     uint32_t allocateSlot(LDefinition::Type type) {

    77         switch (type) {

    78 #if JS_BITS_PER_WORD == 32

    79           case LDefinition::GENERAL:

    80           case LDefinition::OBJECT:

    81           case LDefinition::SLOTS:

    82 #endif

    83           case LDefinition::INT32:

    84           case LDefinition::FLOAT32: return allocateSlot();

    85 #if JS_BITS_PER_WORD == 64

    86           case LDefinition::GENERAL:

    87           case LDefinition::OBJECT:

    88           case LDefinition::SLOTS:

    89 #endif

    90 #ifdef JS_PUNBOX64

    91           case LDefinition::BOX:

    92 #endif

    93 #ifdef JS_NUNBOX32

    94           case LDefinition::TYPE:

    95           case LDefinition::PAYLOAD:

    96 #endif

    97           case LDefinition::DOUBLE:  return allocateDoubleSlot();

    98           default: MOZ_ASSUME_UNREACHABLE("Unknown slot type");

    99         }

   100     }

   102     uint32_t stackHeight() const {

   103         return height_;

   104     }

   105 };

   107 } // namespace jit

   108 } // namespace js

   110 #endif /* jit_StackSlotAllocator_h */

The Tor Browser / file revision